Seal assembly



. Oct. 3, 1967 s. BIALKOWSKI I 3,345,078

I SEAL ASSEMBLY v Original Filed Feb. 21, 1954 INVENTOR.LUDWIKS.BIALKOWSKI United States Patent 2 Claims. (Cl. 277-205) v Thisapplication is a continuation of application Ser. No. 346,487, filedFeb. 21, 1964, now abandoned.

This invention relates to fluid pressure seals useful in hydraulic orpneumatic equipment between relatively static parts. More particularly,the seals of this invention are gasket-type seals of the class in whicha sealing element is statically pressed between two opposing parts.

A seal assembly according to this invention embodies a sealing elementwhich is preferably annular and is specially shaped so that it can sealagainst fluid pressure directed from two different sources. The seal iseffective even if the pressure of the fluid from one source issignificantly different from the pressure of the other source. Moreover,the sealing element maintains the fluid sources separated so that thefluids involved may diflfer from each other and may even be chemicallyincompatible. The sealing element is preferably of resilient metal.

With respect to its structural characteristics, the sealing element ofthis invention has a body of generally C-shaped cross section with threeindependent sealing faces or edges. These edges are preferably verynarrow so as to effect practically a line contact with the adjoiningparts of the assembly. Two of the sealing edges are located at theextremities of the C-shaped body and are both directed in the samedirection to engage a sealing surface of one of the apparatus parts. Thethird sealing edge is directed oppositely on a region of the bodybetween the extremities to engage a sealing surface of the otherapparatus parts. Between the third sealing edge and each of the othertwo edges the body is curved to present a convex surface to the fluidpressure directed against the sealing element. The concave surfaceregions of the sealing element are substantially free of fluid pressurebecause of the sealing engagement of the two edges at the extremities ofthe C-shaped body.

The inventionwill be further described with reference to theaccompanying drawings which show, by way of example, a preferred sealassembly embodying this invention. In the drawings:

FIG. 1 shows a partial axial cross section of a sealing ring ofpreferred design; and

FIG. 2 is a fragmentary axial cross sectional view of a preferred sealassembly embodying the sealing ring of FIG. 1.

The components of the seal assembly in FIG. 2 include an annular metalsealing ring located with two parts 12 and 14 between which the ring 10is axially squeezed. The parts 12 and 14 represented in the drawing maybe any two parts of an apparatus in which fluid pressure is contained.The ring 10 fits in a rabbet 15 in part 12 which is annular about thecenter line C indicated. Part 14 is forced axially against the ring 10by bolt 16 threaded into part 12. The assembly is such that the sealingring 10 is subject to fluid pressure from two different sourcesindicated by the arrows P-1 and P-2 in FIG. 2. Pressure P-l may differsignificantly from pressure P-2. The fluids in which such pressures aregenerated may also be different from each other-e.g. the pressurerepresented by P-1 and P-2 may be fluid presure systems such as oil,water, air, etc. in any combination.

The sealing element or ring 10 is generally thin and is preferably of aresilient alloy steel for ordinary hydraulic equipment. It may be of anymetal which has suflithey may actually come to a sharp point. Edges ofthese cient rigidity, resilience, temperature resistance, and corrosionresistance to meet the particular service conditions.

The sealing ring 10 is in the shape of an annular channel and its crosssection is a generally elongated C-shape. The ring has a radially innersealing edge18, and a radial- 1y outer sealing edge 20 bordering theconcave or channel-shaped face 22 of the ring. On the opposite or convexface 24, approximately along the annular midpoint thereof, there is athird sealing edge 25 which is oppositely directed from the other twosealing edges.

Each sealing edge is in a plane normal to the axis of the ring and edges18 and 20 are in a common plane. Each edge is preferably a polished orcoined plane surface, the radial width of which is less than about 0.010inch wide. Alternatively, these edges may be rounded or shapes provideessentially a line contact against the parts 12 and 14 and requirecomparatively small axial force to make the seal effective. While linecontact is preferred, the advantages of this invention may be realizedin many cases with sealing edges which are much wider, radially,

than the foregoing dimension recommended. Accordingly, this dimension isnot to be regarded as a critical or limiting feature unless specificallystated in a claim. The sealing edges in FIGS. 1 and 2 are drawn with alarger area relative to the remaining portions of the ring than ispreferred in service to better illustrate the shape of the ring.

Edges 18 and 20 are formed on thick marginal portions 27 and 28,respectively, which are chamfered inside and outside at 30, 31, '32 and33 toward the sealing edges. Sealing edge 25 is formed on a thickannular ridge 30 on the convex side 24 of the sealing ring.

The convex side 24 of the sealing ring is shaped in a smooth reverselycurved contour between the sealing edge 25 and each of the chamfers 30and 33. The concave side 22 is generally plane in the region 36 oppositeridge 34, and is then curved through the regions 37 concentrically withthe outside surface. The latter regions blend smoothly into generallycylindrical regions 38 adjoining chamfers 31 and 32.

In the seal assembly of FIG. 2, the sealing edges 18 and 20 abut a planesealing surface 40 on part 12 whereas the sealing edge 25 abuts anopposing plane parallel surface 42 on part 14.

The sealing ring is axially squeezed by tightening bolt 16 to urge part14 toward part 12. The resulting force causes the sealing ring todeflect primarily in the curved portions between ridge 34 and the thickmarginal regions 27 and 28. The actual deflection is very small, theaxial dimension between the sealing edge 25 and the edges 18, 20 beingreduced in the order of only several thousandths of an inch in a typicalinstallation. A fluid-pressure-tight barrier is formed in'this mannerbetween each sealing edge and the abutting surface adequate to preventthe passage of the fluid pressure.

Owing to the resilience of the seal, should the pressure applied to theseal operate to separate parts 12 and 14, the sealing ring can expandslightly to remain in sealing contact with surfaces 40 and 42. However,the pressure from source P-1 acts on the region of the convex side 24between edge 25 and edge 20 in a manner tending to straighten or flattenthis portion of the sealing ring to insure the tight sealing engagementof edges 25 and 20, notwithstanding the resilience of the ring. The sameis true with respect to the force exerted by the pressure P-2 on theconvex surface region of the sealing element between edge 25 and edge18. The concave side 22 of the sealing ring remains substantially freefrom pressure. The mode of operation of the sealing element 10 is thesame even though the pressure sources represented by P-1 and P-2 varywidely from one another.

3 4 The seal assembly may be repeatedly assembled and (e) an annularridge projecting from said central pordisassembled without necessarilydamaging the sealing tion of said body on the side thereof opposite saidelement. thick extremities, said ridge being radially intermedi-Variations in the construction may be made within the ate said twocurved end portions of said body; scope of the claims. 5 (f) a thirdannular line contact sealing edge on said I claim: ridge directedaxially of said sealing element oppo- 1. A seal assembly for staticsealing service in fluid site the aforesaid two sealing edges andengaged pressure equipment, said assembly comprising: with said sealingsurface of the other of said parts;

(a) two parts having laterally spaced, opposing,'plane and parallelsealing surfaces mounted for displacement (g) said metal body of saidsealing element being rerelatively toward each other; silientlydeflectable along the curved end portions of (b) an annular metallicsealing element between said said body in response to an axial loadprovided by sealing surf-aces against which said parts are adapted saidtwo parts. to exert sealing pressure axially of said element, said 4 2.A seal assembly according to claim 1 wherein fluid element having:pressure is directed between said two parts against the (c) an annularrigid resilient metal body having convex side of each of said curved endportions of said a central portion extending radially of the body withbody.

radially outer and radially inner curved end por- References Cited 2o i1 s e 1y 1 11 re a 10 er than said curved portions, and which projectaxially 3139009 6/1964 P 532 of the body to define a generallychannel-shaped cross 3'147'015 9/1964 Hanbac 277- section for said body;FOREIGN PATENTS ((1) two annular line contact sealing edges on said I44,867 2/1928 Norway body, one being on the thick radially outerextremity and the second being on the thick radially inner ex- 2780929/1951 Swltzerland.

tremity, said sealing edges being disposed in a com- LAVERNE D. GEIGER,primary mon plane normal to the axis of said sealing element and bothbeing directed axially of the body and BENHAM LEWIS LENNY Exammers'engaged with said sealing surface of one of said parts; J. S. MEDNICK,Assistant Examiner.

1. A SEAL ASSEMBLY FOR STATIC SEALING SERVICE IN FLUID PRESSUREEQUIPMENT, SAID ASSEMBLY COMPRISING: (A) TWO PARTS HAVING LATERALLYSPACED, OPPOSING, PLANE PARALLEL SEALING SURFACES MOUNTED FORDISPLACEMENT RELATIVELY TOWARD EACH OTHER; (B) AN ANNULAR METALLICSEALING ELEMENT BETWEEN SAID SEALING SURFACES AGAINST WHICH SAID PARTSARE ADAPTED TO EXERT SEALING PRESSURE AXIALLY OF SAID ELEMENT, SAIDELEMENT HAVING: (C) AN ANNULAR RIGID RESILIENT METAL BODY HAVING ACENTRAL PORTION EXTENDING RADIALLY OF THE BODY WITH RADIALLY OUTER ANDRADIALLY INNER CURVED END PORTIONS OF UNIFORM THICKNESS WHICH TERMINATEIN TWO RADIALLY SPACED EXTREMITY PORTIONS WHICH ARE THICKER THAN SAIDCURVED PORTIONS, AND WHICH PROJECT AXIALLY OF THE BODY TO DEFINE AGENERALLY CHANNEL-SHAPED CROSS SECTION FOR SAID BODY; (D) TWO ANNULARLINE CONTACT SEALING EDGES ON SAID BODY, ONE BEING ON THE THICK RADIALLYOUTER EXTREMITY AND THE SECOND BEING ON THE THICK RADIALLY INNEREXTREMITY, SAID SEALING EDGES BEING DISPOSED IN A COMMON PLANE NORMAL TOTHE AXIS OF SAID SEALING ELEMENT AND BOTH BEING DIRECTED AXIALLY OF THEBODY AND ENGAGED WITH SAID SEALING SURFACE OF ONE OF SAID PARTS; (E) ANANNULAR RIDGE PROJECTING FROM SAID CENTRAL PORTION OF SAID BODY ON THESIDE THEREOF OPPOSITE SAID THICK EXTREMITIES, SAID RIDGE BEING RADIALLYINTERMEDIATE SAID TWO CURVED END PORTIONS OF SAID BODY; (F) A THIRDANNULAR LINE CONTACT SEALING EDGE ON SAID RIDGE DIRECTED AXIALLY OF SAIDSEALING ELEMENT OPPOSITE THE AFORESAID TWO SEALING EDGES AND ENGAGEDWITH SAID SEALING SURFACE OF THE OTHER OF SAID PARTS; AND (G) SAID METALBODY OF SAID SEALING ELEMENT BEING RESILIENTLY DEFLECTABLE ALONG THECURVED END PORTIONS OF SAID BODY IN RESPONSE TO AN AXIAL LOAD PROVIDEDBY SAID TWO PARTS.